Electrically operated dimpling attachment



Seht. 7, 1943- P. H. MERRIMAN 2,328,919

ELECTRIGALLY OPERATED DIMPLING ATTACHMENT Filed oct." 1942 INVENTOR. PAUL HOMER MERRIMAN of the operator, other than placing the Patented Sept. 7,

UNITED STAT Es PATENT OFFICE ELCTRICALLY OPERATD' DILIPLING ATTACHMENT Paul Homer Merriman, Rliderwood, Md., assignor to The Glenn L Martin Company,

er, Md., a corporation ofvMaryland Middle Rivl Application october 7, 1942, serial'No. 461,106

claims. (Cli 153-21) This invention relates to audimpling machine,

more particularly to a control for =a dimpling `sheet over the pilot ypin and then operate the air valve of the squeezer which actuates the dimpling tool. Where large` sheets are to be dimpled, it requires both hands of the operator to manipulate the sheet in the machine.

tool extends beyond the ring/ The ring is sup'- ported on bracket Il by spring I2 and arm I3, rod I4 transmits themotion of the' ring to the button of micro-switch I5. Switch I5 is connected in serieswith amaster switch I6, 'a foot pedal safety switch I1, a source of power I8, and time delay switch solenoid I9. Solenoid which operatesthe air valve 2l of the pneumatic control of the'dimpling tool is connected across the solenoid I 9 in the above described circuit. The contacts 22 and 23are made and broken by connector 24. This connector is moved by member 25 which, in turn, is moved upwardly by the core 26 of the solenoid I9. 26 is governed in its notion by its attachment to the diaphragm 21 of the airtight box' 28. Valve 29 may be adjustedt `tov `control the timing of the motion of member 26 and the partsl actuated thereby.

' By the invention herein disclosed, the dimpling operation takes place at the proper time without extra eil'ort vonthe part of the operator.

The invention makes it possible for the dim pling machine operator to handle large sheets and dimple -rows of holes, easily and quickly, as the system is fully automatic.

Since the dimpling tool will be actuated only when the hole in the sheet is over the pin of the dimpling tool, it is impossible to damage the sheet by the inadvertent operation of the machine.

No pedals other than a safety foot pedal are required, which lessens fatigue 'of the'operator.

Further and Aother ,objects will become `ap-4 parent from the description of the accompanying drawing which forms a part of this disclosure` and" in which like numerals refer to like parts.

In the drawing: Fig. 1 shows a dimpling tool partly in section and a schematic representation of the control therefor.

Fig. 2 illustrates a pneumatic dimpling tooL The dimpling tool consists of an anvil I, having a convex surface 2, a bore 3 for the reception of pilot pin 4. The pilot pinis formed in- 'tegrallv with peen 5 and extends `through the rivet hole of the material. Surface G on peen 5 'cooperates with a matingsurfacefon the anvil I to form the dimple in sheet 1. Bushing 8 is urged upwardly by spring 9 to prevent distortion of the sheeted material as described in the above mentioned patent. f

`Ring I! extends around the dimpling tool in In the operation of the device, the master switch I Ii is closed and the foot of the operator is placed on switch I1. When the sheet to be dimpled is placed in the machine, it is'slid along on the pilot pin'4 to a hole in the sheet, around which it fis desired to form a dimple. When the vhole and pin register, the sheet drops over the pin andlthe Weight ofthe sheet presses down. on ring I0 causing push rod I4 touclose switch I5. This energizes solenoid`l9 and since contactor 24 normally closes the circuit to-solenoid 20, the air valve is immediately opened to opervate the dimpling tool. lAfter. a brief interval,-

determined by the diaphragm-21 and the adjustment of bleed valve 29,'the motion of core 26 opens the circuit to solenoid 20 which shuts oif the air valve 2l. Lifting a sheet 1 from the ring IIJ opensthe circuit o n solenoid t9 and the time delay switch resets for the next operation. It should be apparent that-thetime delay switch control forl the is timed to openvbythe adjustment of valve 29.

Thedimpling tool will not be operated until a sheet again slides over the pilot pin. and'presses on ring III.

Fig. 2 illustrates a pneumatic system for operating a dimpling tool for' thepur-pose and in the Amanner described above. l

'Air under pressure is conducted by pipe to. I

valve 3l.- Push rod I4 from ring- Il|moves -the valve so that when passage 32 is opened, a passage .33 is closed, When'psage I32 is opened, l air pressure is transmitted to cylinder 34 and valve :s wmchris normauy open. thus permitting -thepressure to be transmitted through pipe 56 to cylinder-'31 .and piston 35 whichmoves linkage such a position that the pilotpin of the dimpling 39 to voperate valve 2Li 4Piston 40 in cylinder I4 Core . with any similar-tool.

valve 4I. After a predetermined time, rod 46 contacts member 42 onl valve 35 to shut off the supply of air to pipe 36. The air in cylinder 31 escapes through vent 43 when the piston has moved to uncover this vent. Springs 44 and 45 are provided for the` return of pistons 38 and 40 when the pressure is relieved.

The electrical control is very sensitive and is preferred with sheet aluminum where only small pressures are involved.

While this automatic control is illustrated for use with a dimpling tool,v it is intended for use From this disclosure. it should be apparent that the automatic control is adaptable to many other tools and operations.

It is to be understood that certain changes, alterations, modifications and substitutiom can be made without departing from the Vspirit and scope of the appended claims.

I claim as inyinvention: 1. The combination with a power operated tool for forming material, of a trigger adjacent the .forming portion of said tool adapted to control, y Vthe poweriapplied v-to said tool, said trigger being so positioned as to be actuated by the weight of said material only when properly positioned to be formed.

2. An actuating mechanism for the power circuit of a sheet metal working tool-comprising an electric switch positioned to be actuated by theweight of the material in place in the tool, a time delayed switch having a solenoid in series with a source of electric power and the switch, said switch being normally closed and timed to open, and a second solenoid which operates the said moves upwardly with a speed determined by bleed power circuit, controlled by .the time delayed switch whereby the positioning of a sheet of metal causes the lactuation of the power tool and the subsequent deenergizaton of its power circuit.

v3. A control mechanism for the powerA circuit of a sheet metal working tool comprising, an air valve actuated by the weight of the metal sheet in place in the tool, and time controlled -pneumatic means actuated by the air valve to control the power for a single timed full cycle operation of the tool.

4. The combination with a dimpling tool for dimpling sheet metal around holes formed therein, said dimpling tool having an upwardly, ex-

' tending pilot pin over which the sheet of metal drops when the hole` and pin register, of trigger means actuated by the weight of the sheet metal and a. power relay actuated by said trigger to cause the operation of the tool, said trigger means lying suiciently below the tip of the said pin to be protected against actuation until the sheet drops after the pin enters the hole.

5. The combination with a dimpling tool for dimpling sheet metal around holes formed therein, said dimpling tool having an upwardly ex- 

